hynes



L. P. HYNES.

HEATER SYSTEM.

APPLICATION FILED MAY21, was.

1,303,669, Patented May 13, 1919.

2 SHEETS-SHEET I.

L. P. HYNES.

HEATER SYSTEM.

APPLICATION HLED MAY 21. ms.

1,303,669. Patented May 13, 1919.

Y 2 SHEETS-SHEET 2- @WIMW UNITED STATES PATENT OFFICE.

LEE P. HYNES, OF ALBANY, NEW YORK, :ASSIGN TO CONSOLIDATED CAR-HEATING COMPANY, OFA LBANY, NEW YORK, A CORPORATION OF WEST VIRGINIA.

HEATER SYSTEM.

Specification of Letters Patent.

Patented May 13, 1919.

Application filed May 21, 1918. Serial No. 235,769.

To all whom it may concern:

Be it known that I, LEE P. HYNES, a citizen of the Uni-ted States, and a resident of the city of Albany, county of Albany, and State of New York, have invented an Improvement in Heater Systems, of which the following is a specification.

My present invention relates to" heating systems and has especial application to those which are thermostatically controlled. In the accompanying description I have referred exclusively to apparatus which heats a car by the resistance of electric coils included in the circuit at desired times; but nothing in the invention makes it impossible to apply the system to other heating means, on cars or elsewhere, as will be apparent after reading the specification, though its intended use is on a car.

In the operation of such system several features of construction become desirable, and others involve difiiculties which are to be avoided. The current which passes through the thermostat should be small, because that is usually a mercury thermometer and its capacity to control large currents without damage is obviously restricted. The arrangement for closing and opening the circuit of the heater itself should comprise means for passing a large current through a magnet-coil when its armature is to be attracted, and means for reducing the current which is to flow through the magnet after the armature has been attracted; and it is desirable that the current at the relay contacts should be restricted at time of opening so as to diminish the are there. At the same time, these several objects must be accomplished without undue complication of circuits, or an undesirable number of contacts, since every contact increases the liability to derangement from dirt or other intereference with its proper closing or openm All of the objects namedare attained by the apparatus which I will now describe, which embraces in general a heater and a circuit opened and closed by a magnet, which is thrown into or out of circuit by a relay, which in turn is controlled by a thermostat. The relay and thermostat are located in an independent circuit. This may be supplied from the same source of current as the heater, and on the common trolleyoperated continuous current systems this is effective and desirable; in the alternating current systems sometimes used, I may operate this independent circuit by a storage battery, and it is to be understood that my claims are not restricted to an identical source of current for the heater and for the controlling or relay circuit.

In systems heretofore known to me, several of which I have myself devised and which have been patented to me under various dates and numbers, it has been customary to use magnetic main switches which close the heater circuit whentheir coils are energized, the heater circuit being thus nor mally open. The improved construction herein shown maintains the heater circuit normally closed at the contacts of the mainswitch. coil, as it is usually called. It is of course to be understood that there are manually operated switches underthe control of proper employees of the railroad company by which the heating system may be thrown into action or cut out entirely, and these are not herein referred to further; where the term main switch is employed, it is un derstood to be the electromagnetic main switch thus just designated. This arrangement of maintaining the main switch contact closed by means of a spring avoids the overheating of the magnet coil and the waste of current thereby, which amounts to a. substantial quantity, since the current passes through it during all the time that the heater is in operation. This arrangement has many other advantages which will be described later.

The accompanying drawings show diagrammatically the clrcuits of my improved system;

Figure 1 is a diagram showing the contacts and coils in the ordinary collocation;

Fig. 2 is a simplified sketch of the circuits, with an alternative source of current.

Fig. 3 is an arrangement operative with separate alternating or direct current heating circuits, with auxiliary source of current for control circuits.

A is the trolley wire and A the trolley, leading to the main lead A on the car. From this main lead extends a circuit to the contacts 1, 2, of the main switch, which are held closed by means of the spring 3 so as to insure good contact; a blow-out magnet coil 4 is included in series with these contacts, and is of course so disposed that the arc is transverse to the lines of force in the magnetic field, as is customary. This circuit proceeds through the heater B direct to ground, when the contacts 1, 2, are closed, as here shown. Connected to the circuit through the heaters, and in multiple therewith, is another circuit passing through the resistance R the coil 7 of the main switch, and the contacts 5, 6, of the relay, presently to be referred to. As illustrated, this circuit is open at the contacts 5, 6.- Connecting the circuit referred to and the main circuit con trolled by the contacts 1, 2, is another circuit containing a resistance R the oilice of which will presently be described.

In an independent circuit, as indicated in my statement of invention, is the thermostat T, havingthe contacts 9, 10, sealed into theglass of the thermometer in the customary way; these contacts are in series with the relay coil 8, and this circuit is in multiple with a small resistance R by means of the drop in which the current through the independent relay circuit may be controlled; the amount of current passing through the relay coil and thermostat may thus be adjusted to anything desired. In series in this independent circuit is a resistance R of substantial amount, depending upon the voltage of the system. With standard 550 or 600 volt systems, I have used resistances of about 3500 ohms at R and 600 ohms or so at B The drop through the resistance R due to the small current in the independent circuit, will be moderate; and therefore the voltage interrupted upon the thermostat T will be relatively low and the current quite small.

The operation of the parts just described is as follows: When the manually operated switches throwing on the heating apparatus as an integer are closed by the car crew or car-barn inspectors, the contacts 1, 2, are already closed and full current passes at once through the heating coils B. This continues until the temperature of th car rises to such a point that the mercury in the thermostat T touches the contact 9 in the independent circuit of the relay. When this happens, the coil 8 of the relay is energized and closes the contacts 5, 6; this sends current through the coil 7 of the main switch and opens the contacts 1, 2, the arc at these contacts being blown out .by the magnet l, and being also reduced by reason of the fact that the resistance R is arranged in shunt to these contacts and is grounded through the heater coils, so that the current is divided. The heater is not thrown out of circuit entirely; but its entire current supply comes through the large resistance R in series in the circuit of the coil of the main switch, and the resistance R is also now in series with the coils of the heater. The resistance R thus serves to limit the current through the coil 7 and also to reduce very greatly the current in the heater, and with the resistance R now acting in series with it, this heater current is cut down so far as to be substantially negligible. It is manifest that the selection of the resistances would depend upon the voltage of the system and also to some extent upon whether alternating or direct current should be used. For the standard 600-volt continuous current systems, I have used at R 2,000 ohms, at R 2,000 ohms. The resistance of the magnet coil 7 is about 2,000 ohms and magnet coil 8 about 1,250 ohms. There may be some variation in these, dependent upon the current which the designer thinks permissible in the various circuits.

By the arrangements just indicated, it is apparent that only a very small current at low voltage is broken at the thermostat contact 9, when the car cools sufficiently to permit the circuit to be opened. There is no are from this small current, so that no difficulty arises in the operation of the thermostat. As soon as the circuit is opened at the contact 9 the contacts 5, 6, of the relay open, thus open-circuiting the coil 7 and permitting the spring 3 to close the contacts 1, 2, and throw the heater into circuit.

In Fig. 2 the same reference characters refer to the same parts, but I have shown in this an arrangement of storage battery, such as I refer to in my statement of invention. This is shown at D in Fig. 2, and its circuit is controlled by the switches cl, cZ, which it will be observed have contacts in the main line and also in the battery circuit, so that by shifting these switches, the circuit through the resistance R, R ,to the trolley is opened and the coil 8 of the relay and the contacts 9, 10, of the thermostat are connected directly upon the storage battery; so that when th thermostat closes at contact 9 current will be sent through the coil Sand the contacts 5, 6, will be closed as shown in Fig. 1. Opening the circuit of the trolley prevents even the minute loss of current which would otherwise occur through the resistance R, R As pointed out, this is useful on alternating current railway systems, where this current, which is excellently adapted to the heaters and indeed is more efficient for them than continuous current, cannot well be used in the controlling relay, owing to the diiiiculty of satisfactory design for alternat ing current magnets of small capacity.

Fig. 3 covers an arrangement for use on alternating current railways or those operated at extremely high or variable voltages where auxiliary control circuits are provided, and it is desirable to operate the control circuits of the thermostat equipment from an auxiliary source of current. In this arrangement, in order to get the benefit of the drop in current through main coil 7 after the opening of contacts 1 and 2, it is necessary to provide additional interlock contacts 11 and 12, which are normally closed when contacts 1 and 2 are closed, but which open when contacts l and 2 open. While contacts 11 and 12 are closed resistance R in series with main switch coil 7 is shunted out; but when contacts 1 and 2 open and the armature of the main coil 7 is in contact with its core, contacts 11 and 12 open and introduce resistance R in series with coil 7, thereby cutting down the flow of current. The double pole switch DP opens both the circuit of the trolley and of the battery D when the heaters are not required, thus protecting the battery. In case low voltage batteries are used, resistance R may be dispensed with, thus making an additional saving in battery current.

The system of keeping the contacts at the main switch closed by the spring, and hav ing them opened by the current, instead of causing them to be closed by the current and opened by the spring, has great advantages in practice over the reverse method of operation. In systems in severe climates, particulary, it is practically imperative that if the car is to be used at all the heating apparatus shall be operative. Where the current is relied upon'to maintain the heater in circuit, if any part of the control circuit is broken the car must be run into the barn, because it is impossible for the crew to operate the main switch properly; whereas, with my improved system, should any part of the electrically operated devices fail properly to function, the control of the ordinary hand switches by the conductor will keep the system going; when the car gets too hot, he has only to turn off the switch, and turn it on again when it gets too cold, since the contact at the main switch is closed. Another great advantage is that the relay and its thermostatic control are in an independent circuit so that the system may be used even if this independent circuit fails to function properly, or a wire is broken or the like. This is a great advantage on systems where the alternating current is used, and where the storage battery is relied on in the independent circuit.

I have called the control circuit independent and so in effect it is while it is true that in Figs. 1 and 2 it is shown in multiple with the heater circuit, and its main switch in the circuit connected to the heater, it is in fact independent in its operation, since the action of the relay and thermostat do not depend to any degree upon what is going on in the heater circuit or the circuit of the main switch, although they control their actions. This is apparent from the fact which I have stated that the source of current may be a storage battery, as hereinafter stated, or even a primary battery if desired. In other words, this independent circuit does not depend in any sense upon W: either the voltage or" current in the other circuits of the apparatus and has no other relation to them than that it takes current from the nearest available source of supply, when it is connected to the trolley circuit.

Some of the differences between this and former constructions will be apparent from the description and may be indicated as follows: The switch is normally closed by the spring and opened by its coil being energized when the relay contacts close, in which sense I use the term normally closed in my claims; whereas other systems known to me close the circuit of the heaters by the coil being energized, and open it by the spring; the circuit of the main switch coil is independent of and has no effect upon the relay coil and thermostat, whether the circuit of the switch coil be open or closed;

the circuit of the main switch is opened instead of being shunted or short-circuited as in some other systems, an advantage of which is that if the relay makes poor con tact in short-circuiting the main switch, the armature may not be released, since only a small current is needed to hold it up if it has once been attracted, whereas, in my system here described, the main switch coil circuit is positively opened; in direct current operation the main switch coil and heater circuit are connected functionally and operatively, but are independent functionally and operatively of the circuit containing the thermostat and relay.

The systems described all provide for a reduction in current in the main switch coil 7 after the magnet has attracted its armature and opened contacts 1 and 2. This is a great advantage because it prevents overheating of the magnet by the heavy current necessary for starting the armature, but which is not necessary for holding it against the coil. This is accomplished in Figs. 1 and 2 without any additional contacts, while in Fig. 3 additional contacts 11 and 12 are provided for this purpose. It is of course an advantage of systems 1 and 2 that no additional contacts are necessary. In addition to reducing the heating of coil 7, this reduction in current also reduces the work to be done by relay contacts 5 and 6 when they open the circuit of coil 7, as they will close satisfactorily a much larger current than is best to use when they open.

In some of the claims I have used the expression at desired times. By this I do not mean to imply that the switch is in any sense a time switch or that the apparatus works periodically, but that it functions at the time when certain conditions arise. The expression is often used in electrical cases to imply upon the occurrence of this condition, for example, and it is in that sense I use it in this case.

Many obvious changes may be made in the arrangement, which I have described, without departing from the invention disclosed therein, and all such I aim to cover switch, and a thermostat controlling the relay.

3. In a heatingsystem, an electric heater, a main circuit from a source of current to the heater, normally closed contacts in said circui-t, and an electro-magnet for opening said contacts ,at desired times; in combination with a relay and thermostat in an independent circuit, the relay provided with contacts which when closed passcurrent through the coil-of the electro-inagnet, and therthermostat having contacts which When closed pass current through the coil of the relay.

4. In a heating system, an electric heater, a normally closed main circuit including the heater, an electro-magnet for opening the main circuit at-desired times, a relay controlling the electro-magnet, and a thermostat controlling the relay; the electro-magnet being provided with means for reducing the current flow therethrough after its armature is attracted.

5. In a heating system, an electric heater, a'normally closed circuit including the electric heater, an electro-magnet for opening the normally closed circuit at desired times, a relay for opening and closing the circuit of the electro-magnet, and athermostat for actuating the relay; theelectro-magnet having a resistance in series therewith, and a resistance shunting its coil when the magnet circuit is closed.

6. In a heating system, an electric heater, a normally closed circuit including the electric heater, an electro-magnet for opening the normally closed circuitat desired times, a relay for opening and closing the circuit of the electromagnet, and a thermostat in circuit with the relay; the electro-magnet having a resistance in series therewith, and

' a resistance shunting the magnet coil when its circuit is closed, the said resistances being in series between the source of current and the heater.

7 In a heating system, a source of current, an electric heater in a circuit normally closed from the source of current to ground, a second circuit in parallel with the heater and containing an electro-magnet arranged to open the heater circuit at desired times, a resistance in series with-the electro-magnet and in shunt to the heater circuit, and a second resistance in series with the first and shunting the contacts operated by the elec' tro-magnet; with a relay controlling the electromagnet, and a thermostat controlling the relay, the thermostat and relay being rent, an electric heater, a circuit through the electric heater from the source of current to ground, normally closed contacts in sald circuit, an electro-magnet for'opening said contacts at desired times, contacts in the circuit of the electro-magnet, and a relay and thermostat in an independent circuit for controlling said contacts; the relay and thermostat belng in series wlth a resistance,

and in shunt to another resistance.

10. In a heating system, a source of current, a heater, a circuit from the source of current through the heater, normally closed contacts in said circuit, a second circuit in shunt to the heater circuit containing an electro-magnet for opening the normally closed contacts of the heater circuit, a resistance in series in the circuit of the electromagnet, asecond resistance in shunt to the heater-circuit contacts and to the electromagnet so connected that the two resistances are in series and grounded through the heater when the main heater circuit is opened by the magnet; and means for opening the main heater circuit, such means responsive to temperature.

11. In a heating system, a source of current, a heater, a circuit from the source of current through the heater, normally closed contacts in said circuit, a: secondcircuit in shunt to the heater circuit containing an electro-magnet for opening the normally closed contacts of the heater circuit, a resistance in series in the circuit of the electro-magnet, a second resistance in shunt t the heater-circuit contacts and to the electromagnet so connected that the two resistances are in series and grounded through the heater when the main heater circuit is opened by the magnet; and a relay and thermostat controlling the circuit of the electro-magnet.

1.2. In a heating system, a source of our rent, a heater, a circuit from the source of current through the heater, normally closed contacts in said circuit, a second circuit in shunt to the heater circuit containing an electro-magnet for opening the normally closed contacts of the heater circuit, a resistance in series in the circuit of the electromagnet, a second resistance in shunt to the, heater circuit contacts and to the electromagnet so connected that the two resistances are in series and grounded through the heater when the main heater circuit is opened by the magnet; and contacts controlled by a relay and thermostat for closing the circuit of the electro-magnet when the main heater circuit is to be opened.

13. In a heating system, a source of current, a heater, a circuit from the source of current through the heater, normally closed contacts in said circuit, a second circuit in shunt to the heater circuit containing an electro-magnet for opening the normally closed contacts of the heater circuit, a resistance in series in the circuit of the electromagnet, a second resistance in shunt to the heater-circuit contacts and to the electromagnet so connected that the two resistances are in series and grounded through the heater when the main heater circuit is opened by the magnet; and a relay and thermostat in series in an independent circuit, controlling the circuit of the electromagnet.

14. In a heating system, a source of current, a heater, a circuit from the source of current through the heater, normally closed contacts in said circuit, a second circuit in shunt to the heater circuit containing an electro-magnet for opening the normally closed contacts of the heater circuit, -a resistance in series in the ,circuit of the electromagnet, a second resistance in shunt to the heater circuit contacts and to the electromagnet so connected that the two resistances are in series and grounded through the heater when the main heater circuit is opened by the magnet; and an independent circuit containing a relay, contacts actuated by the relay for closing the circuit through the coil of the electro-magnet, and a thermostat controlling the action of the relay, the relay and thermostat being in an independent circuit containing a resistance in series with the coil of the relay and thermostat, and a second resistance in shunt thereto.

In testimony whereof, I have signed In name to this specification this 18th day of May, 1918.

LEE P. HYNES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

